perror(3)perror(3)Name
perror, strerror, sys_errlist, sys_nerr - system error messages
Syntax
void perror(s)
char *s;
int sys_nerr;
char *sys_errlist[];
#include <string.h>
char *strerror(err)
int err;
Description
The subroutine produces a short error message on the standard error
file describing the last error encountered during a call to the system
from a C program. First the argument string s , if it is not a null
pointer, is printed followed by a colon and a space; then the message
and a new line are printed. Most usefully, the argument string is the
name of the program which incurred the error. The error number is
taken from the external variable errno which is set when errors occur
but not cleared when nonerroneous calls are made. For further informa‐
tion, see
To simplify variant formatting of messages, the vector of message
strings sys_errlist is provided; errno can be used as an index in this
table to get the message string without the new line. The sys_nerr is
the number of messages provided for in the table; it should be checked
because new error codes may be added to the system before they are
added to the table. The function will also return a pointer to the
message text for a given error number.
See Alsointro(2), psignal(3)perror(3)